Template Override and general template issues

Hello, I'm having a couple of issues:

1) I'm trying to create a template override, and I followed the instructions here: http://docs.stackideas.com/administrators/templating/template_overrides
Well, when I create the file style.css (even if the file is empty) at the specified location, the template gets all 'messed up'. Please check images 'before.png' and 'after.png'.
If I delete style.css inside /templates/MY_JOOMLA_TEMPLATE/html/com_easysocial/styles, then everything is normal again.
This is my first issue.


2) Now the second issue: When everything is ok (please see the same image before.png) I see this strange blue rectangle expanding outside to the right. See in the image the rectangle to the right of the search field (in portuguese it is written 'pesquisar').
How can I remove this rectangle?

The site is http://www.redevegetariana.com.br/index.php/community and I'm using Yootheme template Frequency.

Any ideas?

Thanks.